Proctor Research /uv light sap cleansing

[sugarmountain]

Has anyone tried the uv light exposer on sap thing to make lighter syrup? I have searched around but nothing, was wondering if Proctor Research has done any tests on this? If anyone has'nt allready, check out uvm proctor research web sight lots of great stuff on there.

[DrTimPerkins]

Has anyone tried the uv light exposer on sap thing to make lighter syrup? I have searched around but nothing, was wondering if Proctor Research has done any tests on this? If anyone has'nt allready, check out uvm proctor research web sight lots of great stuff on there.

What UV light treatment does is kill microrganisms. Microrganisms (bacteria, yeast, fungi) convert some of the sucrose in sap into invert sugar, which darkens more upon heating, resulting in darker syrup.

The original reseach on this was done by Dr. Mariafranca Morselli several decades ago. More recent work has been done by Dr. Brian Chabot of the Cornell Maple Program and published in a Maple Digest article a few yrs ago.

A few equipment manufacturers do sell UV equipment. The best is probably the "Sap Steady", as it has very high output bulbs and good exposure (very thin layer of sap around the exposure bulb). The units made for water treatment do not function nearly as well (liquid layer is too thick), but will help a little bit. UV lights suspended above sap do next to nothing, as the penetration of UV light into sap is very low to achieve an effective kill rate.

[Bucket Head]

Dr. Chabot commented at Cornell's facility in Lake Placid during the N.Y. maple tour a couple of years ago that the sap steady unit (made by Oesco I beleive) is the only UV light out there that does "a complete kill" on the sap. They have one in use there also.

Steve

[sugarmountain]

Thanks for the info. Im suprized more research hasnt been done as old as the idea is?

[BryanEx]

The Oesco web site says call for price. Anyone have a "ball park" figure on what it's worth? I sure could use it but likely way out of my league price wise.

[Bucket Head]

I'm almost certain the big one (30gpm) was a little over three grand. There was one on display at V.V.S. last year, or the year before.

Steve

[DrTimPerkins]

Thanks for the info. Im suprized more research hasnt been done as old as the idea is?

No more research needs to be done. The technology is pretty simple and the results are very straightforward. In brief, UV treatment, if done properly, works just fine to kill microrganisms. The better device you use, the more exposure of the sap to the UV light you get, the better the results. There was research done a while back (Morselli), and some newer stuff as well (Chabot). Both found basically the same thing. Anything you can do to reduce microbial loads in your sap will result in lighter syrup.

For those who might be wondering....Cornell did some related work with ozone. Ozone works well to sanitize water. Turns out it doesn't work much at all with sap. The sugar apparently provides a protective effect.

[Bucket Head]

Dr. Tim,

Do you know how the Sap Steady unit exposes more sap to the UV light? I know the 30gpm model is physically bigger than most lights, but it is shaped exactly the same as the smaller water treatment models. (Like the one I have that was sold by Small Brothers but is an H2O unit) How can it expose "more" if its still cylindrical in shape?

Also, if Dr. Chabot says it is a "complete kill" unit, do you have any idea what percentage "kill" those of us are getting with the units made for water? Like you said it helps, but just how much?

Thanks,
Steve

[DrTimPerkins]

Do you know how the Sap Steady unit exposes more sap to the UV light? I know the 30gpm model is physically bigger than most lights, but it is shaped exactly the same as the smaller water treatment models. (Like the one I have that was sold by Small Brothers but is an H2O unit) How can it expose "more" if its still cylindrical in shape?

First off, for those who are not familiar with these devices, a UV unit works by having a UV bulb encased within a central housing made of quartz (which is UV transparent). The sap flows between the UV bulb housing and the outer unit casing in a thin film of sap. UV can only penetrate a very thin layer of water or sap and still have enough energy to kill microrganisms. So a better exposure of UV is achieved by having higher output of UV, a thin layer of sap, and low flow rates.

I believe the Sap Steady units achieve a higher kill rate primarily for three reasons:
- it has several UV bulbs or stronger bulbs within the housing and
- it has a thinner column of sap surrounding the central housing unit than the standard household units.
- it has a stated flow rate for use


Also, if Dr. Chabot says it is a "complete kill" unit, do you have any idea what percentage "kill" those of us are getting with the units made for water? Like you said it helps, but just how much?

Very difficult to tell without actually measuring it due to the large number of variables: the make/model of your unit specifying the power output, the number, output rating and age of the bulbs (they should be replaced every couple of years as they degrade over time), the flow rate of sap through the unit, how well the sap is filtered prior to going into the unit (best to filter the sap BEFORE it goes into the UV unit), how clean the quartz housing is, the microbial loading of the sap, etc. In general, the units designed for water will achieve some reduction in sap microbial loads, but under most circumstances will not achieve complete kill (it will be better with fairly clean sap, a new bulb, and relatively slow flow rates).

So are the water purification units worthless? No....not at all. Even a unit that is designed for water (which we have at UVM PMRC) will help keep the microbial populations down and help to make lighter syrup. To use them, change the bulb every few years, filter the sap well before it goes into the UV unit, clean the housing every now and then, and use a pump with a modest flow rate if you can. Or....set them up as recirculation devices.

Three CAUTIONS.
1. Any UV unit can heat up the sap a little bit.
2. Wear eye protection when viewing the light from a UV unit.
3. Be careful with any electrical device around liquid.

[Jeff E]

Thanks for the info on this. Do these units include the circulating pump?
Do most users treat the sap on its way into storage tanks or do you continually circulate the sap from storage tanks through the UV light?

Thanks

BIGGG SAAAPPP is coming soon, get ready

[DrTimPerkins]

Thanks for the info on this. Do these units include the circulating pump? Do most users treat the sap on its way into storage tanks or do you continually circulate the sap from storage tanks through the UV light?

I don't believe the units typically come with a pump.

People generally use them to treat sap on the way to the storage tank (post-filter). Some do circulate though. Either way will work.

[Bucket Head]

Just some advice for the small UV unit users out there. If you bought a used unit or are replacing a bulb, you really have to make sure you have/get the right bulb. Last year I replaced my bulb (with what its supposed to have) and after talking with Atlantic Ultraviolet, I found out I did not have the 40w HO bulb that it was designed for. If you mistakenly put a lower wattage bulb in your reducing your kill rates before you even turn it on! Just like regular bulbs, some UV lights have the same outside dimensions but different wattages.

Also, my UV unit is rated for 7gpm, but all I could find was a 5gpm pump. But that works in my favor since I've slowed the sap down a little bit the UV light is working on the sap just a little bit longer than if it was passing the full 7gpm.

And like Dr. Tim says, filter first and takem' apart and clean them! You should have seen the dirt and scale build-up on the crystal tube and in the housing of mine. Simply disgusting, but more importantly, it could not have been doing what it was supposed to be with all that in there. Actually, you add bacteria if the housing is filthy. With the wrong bulb and all the dirt, that unit was'nt killing any bacteria- it was just scaring it a little bit.

Steve

[delivron]

Dr. Perkins:

When I read the ad for the Sap Steady it implies that the bacteria are using the sugar contact of the sap to live thus reducing the sugar content and increasing the boil time and increasing the cost to produce syrup. Is that a correct assumption? Is bacteria really an issue today since so many producers are now making lighter syrup any way? Producers are holding syrup shorter times, using translucent tubing, and process sap in an RO. Additionally almost all sugar makers with over 3000 taps now use RO is this a Sap Steady recommended producers accessory to reduce boiling costs? I do understand it could improve the grade of syrup and possibly improve the ability of the syrup to hold grade longer.
Why don't we see this type of equipment in every sugarhouse?

http://www.cidersure.com/sapsteady0202.jpg

[Schiefe4]

Anyone care to comment on Delivron's question?

[happy thoughts]

He asked a few questions. I'll take a stab at some of them.

Yes, bacteria will feed on sap sugars especially if the sap is not kept cold and/or held for any length of time just like milk would.

RO doesn't remove bacteria and RO'd sap needs to be boiled within a few hours because, pretreated or not, it spoils quickly. But higher sugar content sap is still going to produce higher sugar concentrate than sap where sugar was lost to microbial feeding. So some savings in time and energy costs should still hold.

I don't think UV treatment will help much in holding syrup grade. When syrup of correct density is packed and sealed at proper temps and stored in a cool place out of strong light in non porous containers, (not plastic), loss of grade shouldn't be much of a problem. Boiling at syrup temps is pretty effective killing bacteria.

If not used more, my guess would be cost effectiveness vs more careful handling, storage, and quicker processing as Delivron already mentioned. Lighter syrups are also being produced with air injection which I imagine is cheaper and requires less maintenance than a UV unit.

[lew]

In my experience you used to see more UV lights in more sugarhouses prior to the extensive use of Ro's. Sap was often times backed up waiting to be processed during big runs and would make darker syrup after the storage time than it would have if processed right away if you did not have a UV light. they had their day in the sun, but with the advent of big RO's that can remove hundreds to thousands of gallons of water per hour, there is little need to store sap in larger operations.

[DrTimPerkins]

Why don't we see this type of equipment in every sugarhouse?

I apologize for not catching this post when it appeared, however besides the answers already given....have you seen the price of these things? It might kill the microbes, but it'll sure knock you back some too. Not even sure if they're still making them....I thought I'd heard that they weren't producing them any more. Vicious cycle thing....price is high, fewer of them sell, that increases the cost of production, put price up to meet production costs and maintain margins, sell fewer units,....rinse, repeat.

[lew]

Last I heard ( a few years ago). They dont have a supply of tem on hand, but will make to order.

[wildlifewarrior]

Is this the same process as cold pasteurization? From my understanding it is similar, but I may be misinterpreting something.

Mike

[DrTimPerkins]

Is this the same process as cold pasteurization? From my understanding it is similar, but I may be misinterpreting something.

Similar. Cold pasteurization is typically done either by placing the food under extremely high pressures for a period of time (this may not kill all spores) or by exposing the food material to ionizing radiation (electron beam, x-rays, gamma rays). UV could be used to irradiate some things, like sap or water, but really isn't used in too many industries due to the lack of penetration (as compared to x-rays or gamma rays) beyond a very thin surface layer (so it can work to sterilize fruit surfaces). In sap it can work if the flow rate and the exposure is correct.

Just to clarify a bit. I'd like to be sure it is clear that the work testing the UV Sap Steady was done by Dr. Brian Chabot of the Cornell Maple Program. http://maple.dnr.cornell.edu/pubs/SapSteadyUVUnit.pdf

[jimsudz]

I just purchased this from a local producer who's husband past this spring. It was built by Phil Hartman, it may be serial #001. It is the smaller of the models he built. I was hoping to off load from truck 425g through the uv and then to storage tank. Does anyone have one like this? How many gallons /minute will go through it on gravity.I was told about 6 gallons not sure if that is correct.

[Bucket Head]

What size fittings are the inlet and outlet? I had a unit that had 3/4" male pipe thread fittings on it and it was rated at 7 gallons per minute. That rating must have been with a pump in front of it. I would guess gravity would be quite a bit less. Think of how slow the flow is with a garden hose siphoning. You would need a lot of head and/or large diameter hose/pipe inorder to flow a lot on gravity. However, faster flow is counter productive when it comes to U.V. treatment.

Steve

[Kara]

Looking for the best way to give sap the longest shelf life.....

1. Any new information or studies on UV applications with regards to Maple Sap? Does, or does it not, work? And to what extent? What shelf life does it provide?

I know the Sap Steady had addressed this, however that was 2007..wondering if research had been done recently on current UV systems on the market.

2. Any studies done on HTST pastuerization versus UHT with regards to sap? We know UHT works, but is HTST just as good?

3. What is the best known way to make sure sap has the longest shelf life? I'm guessing UHT - correct?

Thanks!
Sincerely,
Dazed and confused.

[mellondome]

Shelf life? are you asking about actual siting sap in a bottle on a shelf or in a tank waiting to boil?